1 # SPDX-License-Identifier: GPL-2.0
3 # Kbuild for top-level directory of the kernel
4 # This file takes care of the following:
6 # 2) Generate timeconst.h
7 # 3) Generate asm-offsets.h (may need bounds.h and timeconst.h)
8 # 4) Check for missing system calls
9 # 5) Generate constants.py (may need bounds.h)
12 # 1) Generate bounds.h
14 bounds-file := include/generated/bounds.h
16 always := $(bounds-file)
17 targets := kernel/bounds.s
19 # We use internal kbuild rules to avoid the "is up to date" message from make
20 kernel/bounds.s: kernel/bounds.c FORCE
21 $(call if_changed_dep,cc_s_c)
23 $(obj)/$(bounds-file): kernel/bounds.s FORCE
24 $(call filechk,offsets,__LINUX_BOUNDS_H__)
27 # 2) Generate timeconst.h
29 timeconst-file := include/generated/timeconst.h
31 targets += $(timeconst-file)
33 quiet_cmd_gentimeconst = GEN $@
34 define cmd_gentimeconst
35 (echo $(CONFIG_HZ) | bc -q $< ) > $@
37 define filechk_gentimeconst
38 (echo $(CONFIG_HZ) | bc -q $< )
41 $(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE
42 $(call filechk,gentimeconst)
45 # 3) Generate asm-offsets.h
48 offsets-file := include/generated/asm-offsets.h
50 always += $(offsets-file)
51 targets += arch/$(SRCARCH)/kernel/asm-offsets.s
53 # We use internal kbuild rules to avoid the "is up to date" message from make
54 arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \
55 $(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE
56 $(call if_changed_dep,cc_s_c)
58 $(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE
59 $(call filechk,offsets,__ASM_OFFSETS_H__)
62 # 4) Check for missing system calls
65 always += missing-syscalls
66 targets += missing-syscalls
68 quiet_cmd_syscalls = CALL $<
69 cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
71 missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
75 # 5) Generate constants for Python GDB integration
78 extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
80 build_constants_py: $(obj)/$(timeconst-file) $(obj)/$(bounds-file)
81 @$(MAKE) $(build)=scripts/gdb/linux $@
83 # Keep these three files during make clean
84 no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)